Mistake proof an operational process

This unit of competency covers the skills and knowledge required to make changes to own and others work in a work area which prevents errors and/or backsliding to a pre-improvement level of practice.


This unit applies to a person who needs to analyse a process that a team is responsible for and determine methods of mistake proofing it (e.g. ensuring it only produces product within an acceptable range or error-free transport and storage of goods). The person will typically be a technical expert, team leader or be in a role where they have sufficient technical understanding of processes in their own work and that of others to be able to mistake proof the production process in their area. After improvement activities have been undertaken these improvements need to be sustained.

This unit requires the application of skills associated information gathering and analysis. Initiative, enterprise and problem solving are also required to identify mistakes and determine strategies for eliminating them. This unit also requires communication and teamwork skills to ensure mistake proofing strategies are implemented and self-management and learning skills to continually reflect on and integrate feedback about the effectiveness of strategies.


Not applicable.

Elements and Performance Criteria


Analyse process


Identify sources of variability/non-conformance in the process


Identify critical control points in process


Analyse causes of variability/non-conformance


Develop preventative techniques/systems


Liaise with team members and other people to develop mistake proof options for performing operation


Test and validate mistake proofing options


Implement permanent fix


Liaise with relevant people to have systems/procedures changed to implement solution


Liaise with relevant people to implement the solution


Liaise with relevant people to ensure self and others in the team or work area have an appropriate skills set


Follow through to ensure implementation occurs


Monitor implementation


Critically observe the implementation


Compare the results of the implementation against the expected outcomes


Modify solution to improve outcomes


Ensure procedures reflect change


Ensure training/assessment reflects change


Audit change at agreed period/cycle


Take action on any observed deviation


Seek improvements


Observe changes


Analyse process again, if required, to ensure improvements are sustained

Required Skills

Required skills

Required skills include:

communicating with team or work group members, technical support personnel and other relevant staff

explaining mistake proofing and related concepts

facilitating input of others and encouraging acceptance of changes

analysing and visualising operations in terms of flow and contribution to customer outcomes

solving problems to determine root cause of errors and possible solutions

analysing and interpreting information about errors and mistake proofing options in terms of cost, feasibility, regulations and value to the customer

suggesting design changes to operations and products that eliminate the potential for errors

suggesting mechanisms or procedures that warn of errors where operations cannot be designed to eliminate errors,

Required knowledge

Required knowledge includes:

mistake proofing concepts, including, in priority order:

eliminate the possibility of the error via changes to the process

prevent the error from occurring via physical or virtual barriers

reduce likelihood of the error by encouraging correct action

mitigate the impact of the error if it does occur

understanding of processes undertaken by team

factors in the processes which may cause variability

methods of controlling the variability in the process

mistake proofing methods relevant to the process/product

Evidence Required

The evidence guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, range statement and the Assessment Guidelines for the Training Package.

Critical aspects for assessment and evidence required to demonstrate competency in this unit

A person who demonstrates competency in this unit must be able to provide evidence of the ability to:

analyse variability and non-conformances

identify, analyse and evaluate information from a variety of sources to identify errors and options for mistake proofing

facilitate implementation of mistake proofing activities that reduce waste

facilitate sustaining the mistake proofing activities.

Context of and specific resources for assessment

Assessment of performance must be undertaken in a workplace using or implementing one or more competitive systems and practices.

Access may be required to:

workplace procedures and plans relevant to work area

specifications and documentation relating to planned, currently being implemented, or implemented changes to work processes and procedures relevant to the assessee

documentation and information in relation to production, waste, overheads and hazard control/management

reports from supervisors/managers

case studies and scenarios to assess responses to contingencies.

Method of assessment

A holistic approach should be taken to the assessment.

Competence in this unit may be assessed by using a combination of the following to generate evidence:

demonstration in the workplace

workplace projects

suitable simulation

case studies/scenarios (particularly for assessment of contingencies, improvement scenarios, and so on)

targeted questioning

reports from supervisors, peers and colleagues (third-party reports)

portfolio of evidence.

In all cases it is expected that practical assessment will be combined with targeted questioning to assess underpinning knowledge.

Where applicable, reasonable adjustment must be made to work environments and training situations to accommodate ethnicity, age, gender, demographics and disability.

Guidance information for assessment

Assessment processes and techniques must be culturally appropriate and appropriate to the oracy, language and literacy capacity of the candidate and the work being performed.

Range Statement

The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.

Competitive systems and practices

Competitive systems and practices may include, but are not limited to:

lean operations

agile operations

preventative and predictive maintenance approaches

monitoring and data gathering systems, such as Systems Control and Data Acquisition (SCADA) software, Enterprise Resource Planning (ERP) systems, Materials Resource Planning (MRP) and proprietary systems

statistical process control systems, including six sigma and three sigma

Just in Time (JIT), kanban and other pull-related operations control systems

supply, value, and demand chain monitoring and analysis


continuous improvement (kaizen)

breakthrough improvement (kaizen blitz)

cause/effect diagrams

overall equipment effectiveness (OEE)

takt time

process mapping

problem solving

run charts

standard procedures

current reality tree

Competitive systems and practices should be interpreted so as to take into account:

the stage of implementation of competitive systems and practices

the size of the enterprise

the work organisation, culture, regulatory environment and the industry sector

Mistake proofing

Mistake proofing is based on the concept of zero defects. The first priority is to eliminate the possibility of an error occurring. However, where this is not feasible mistake proofing can be used to reduce the occurrence of errors and/or to minimise their impact.

Mistake proofing should target an error in the following priority order:

eliminate the possibility of the error via changes to the process

prevent the error from occurring via physical or virtual barriers,

reduce likelihood of the error by encouraging correct action (e.g. through warning systems)

mitigate the impact of the error if it does occur

Mistake proofing is also called error proofing or baka-yoke or poka-yoke

Options for mistake proofing

Factors to consider when prioritising options for mistake proofing will vary according to the process and may include:

success rate in eliminating errors


skills required by employees


capacity to reduce waste


Procedures may include:

all work instructions

standard operating procedures


batch sheet

temporary instructions and similar instructions provided for the operation of the plant

good operating practice as may be defined by industry codes of practice (e.g. good manufacturing practice (GMP) and responsible care)

government regulations

Procedures may be:

written, verbal, computer-based or in some other format


Unit sector

Competitive systems and practices

Employability Skills

This unit contains employability skills.

Licensing Information

Not applicable.